When the Sun goes down, the solar dishes stop generating power (photovoltaic systems stop working immediately, but solar thermal systems may continue working for some time after the sunlight has gone, because of the heat stored up). That presents the problem of storing the electricity generated during the day so that it can be used at night. It's especially important if people are likely to have plug-in battery electric vehicles that they charge overnight, for commuting by day.
Several well-tried solutions exist, one being pumped-storage hydroelectricity. Water would be pumped from a low reservoir to a high reservoir during the day, and then allowed to fall back into the low reservoir at night, driving turbines as it went. We haven't worked out where our water's going to come from yet, but we will have some, that much is certain. 80% of the electricity used to pump the water is recovered via the turbine.
If large numbers of people are charging battery-powered vehicles at night, we'll be cutting it a bit fine on the energy-for-transport front, so we'd want to avoid that situation. One way is to charge more for electricity at night -- the opposite of what obtains in most cities -- so that people are encouraged to draw from the grid during the day time rather than at night, whenever possible.
Other strategies involve types of transport systems and infrastructure, and planning that minimises commuting. These, though, are for another day.
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